FXUS63 KDLH 141939 AAC
AFDDLH
AREA FORECAST DISCUSSION...UPDATED
NATIONAL WEATHER SERVICE DULUTH MN
139 PM CST MON DEC 14 2009
.UPDATE...
WE ISSUED A WIND CHILL ADVISORY FOR TONIGHT AND EARLY TUESDAY FOR
NORTHEAST MINNESOTA AND THE ENTIRE DULUTH/SUPERIOR AREA. THE
COMBINATION OF A PERSISTENT BREEZE AND SUBZERO TEMPERATURES WILL
RESULT IN WIND CHILLS BETWEEN 25 AND 40 BELOW FOR THE ADVISORY
AREA. ACCUMULATIONG SNOW ASSOCATED WITH A DEPARTING LOW...NOW OVER
THE LOWER LAKES...HAS ENDED. WINDS ARE EXPECTED TO VEER AND DRY
AIR IS EXPECTED TO MOVE ACROSS WESTERN LAKE SUPERIOR...LIMITING
SNOWFALLS FROM LAKE-EFFECT SHOWERS AND ALSO KEEPING THE STRONGEST
OF THOSE SHOWERS OUT OVER THE WATER.
&&
.PREV DISCUSSION... /ISSUED 1154 AM CST MON DEC 14 2009/
UPDATE...FOR 18Z TAF DISCUSSION.
AVIATION...18Z TAF ISSUANCE...KHYR WILL SEE LINGERING MVFR VSBYS
IN -SN...WITH VFR CIGS. THERE WILL BE A WINDOW OF MVFR AT KBRD
WITH LIGHT SNOW SHOWERS PUSHING THROUGH CENTRAL MINNESOTA THIS
AFTERNOON AHEAD OF A WEAK MID LEVEL DISTURBANCE. THESE MAY ALSO
IMPACT KHYR/KDLH LATER THIS AFTERNOON. THE MAIN UPPER LEVEL WAVE
WILL THEN MOVE THROUGH OVERNIGHT...WITH LITTLE MORE THAN LOW VFR
CLOUD. OTHERWISE...VFR CONDITIONS WILL PREVAIL THROUGH TAF PERIOD
WITH MID LVL CLOUDS AROUND 6-8 KFT BEFORE CLEARING NEAR THE END OF
THE PERIOD.
PREV DISCUSSION... /ISSUED 937 AM CST MON DEC 14 2009/
UPDATE...ADDED A SMALL CRAFT ADVISORY (SCA) FOR THE SOUTH SHORE FOR
TONIGHT AND THROUGH ALL OF TUESDAY. NORTHWEST WINDS WILL INCREASE
OVER WESTERN LAKE SUPERIOR TONIGHT WITH A PUSH OF CAA WILL CREATE
UNSTABLE LOW LEVEL LAPSE RATES. WE DID NOT ISSUE A SCA FOR THE
NORTH SHORE YET DUE TO OFFSHORE WINDS...BUT THIS AFTERNOON'S
ISSUANCE AND TONIGHT'S WILL RECONSIDER CRITERIA FOR WINDS IN THESE
AREAS...AS RIGHT NOW WE ARE EXPECTING 15 TO 20 KT ON THE NORTH
SHORE. COULD BE HIGHER GUSTS WHICH WOULD WARRANT THE SCA. /DONOFRIO
PREV DISCUSSION... /ISSUED 858 AM CST MON DEC 14 2009/
UPDATE...
WINTER WEATHER ADVISORIES ARE EXTENDED UNTIL NOON OVER BOTH THE
INLAND COUNTIES AND GOGEBIC RANGE COUNTIES OF NORTHWEST WISCONSIN.
SYNOPTIC SNOW IS EXPECTED TO LINGER UNTIL UPPER SUPPORT DISAPPEARS
ABOUT NOON TODAY. LIGHT SYNOPTIC SNOW WILL SEED AND ENHANCE LAKE
CONVECTION BUT WE DO NOT EXPECT ANY HEAVY AMOUNTS TODAY.
PREV DISCUSSION... /ISSUED 331 AM CST MON DEC 14 2009/
DISCUSSION...THE NORTHERN FA IS UNDER THE INFLUENCE OF A SFC
RIDGE OF HIGH PRESSURE ALONG THE INTERNATIONAL BORDER WHERE A
PARTLY CLOUDY SKY RULES. OVER THE SOUTHERN THIRD OF THE FA...SNOW
IS FALLING IN RESPONSE TO THE SFC LOW MOVING INTO MISSOURI
ATTM...UPPER LEVEL VORT MAX CROSSING MN INTO WI. SNOW IS
DIMINISHING OVER THE SW QUAD OF THE FA AS BEST FORCING IS ALREADY
MOVING AWAY. THE SNOW WILL CONTINUE TO ABATE EARLY THIS MORNING
AND HAVE ADJUSTED THE END TIME TO THE ADVISORY TO 15Z/9 AM. SOME
SNOW MAY LINGER OVER NW WI INTO THE AFTERNOON...BUT WITH COLDER
AIR MOVING INTO THE AREA...ADDITIONAL AMOUNTS WILL BE MINIMAL.
ATTENTION THEN SHIFTS TO THE SOUTH SHORE OF LAKE SUPERIOR AS A NW
WIND COMBINES WITH THE COLDER AIR TO INITIATE LES SHOWERS TONIGHT.
ANOTHER 1 TO 2 INCHES IS POSSIBLE FROM ASHLAND TO HURLEY AND THE
APOSTLE ISLANDS TONIGHT. DRY HIGH PRESSURE SETTLES OVER THE FA ON
TUESDAY AND SHUTS OFF THE LES.
EXTENDED...WEDNESDAY THROUGH FRIDAY.
AN INCREASING LLJ OVER WRN MN TUESDAY NIGHT WILL ALLOW FOR TEMPS
IN NC MN TO BOTTOM OUT BY 06/08Z WED...THEN REBOUND BY DAY BREAK.
RAN A NON-DIURNAL TEMP TREND FOR WRN ZONES FOR THIS PERIOD. ZONAL
70-80 KT MID LVL FLOW AND POLAR JET OVER THE UPR MIDWEST WILL KEEP
LINGERING SMALL POPS FOR LIGHT SHSN/FLURRIES THROUGH MUCH OF THE
WEEK. A LACK OF MOISTURE/SOURCE OF FORCING THROUGH MIDWEEK WILL
KEEP ANY ACCUMULATION UNDER A HALF INCH WITH PASSING SHORT WAVES.
LONG TERM MDLS IN DECENT AGREEMENT THAT FETCH/LAPSE RATES BECOME
FAVORABLE FOR A PERIOD OF LK EFFECT/ENHANCED SN OF AN INCH OR TWO
OF ACCUM ALONG THE N SHORE OF LK SUPERIOR WED NIGHT THROUGH THURS.
&&
.POINT TEMPS/POPS...
DLH 6 -7 2 -11 / 10 10 10 10
INL -9 -21 -9 -21 / 10 10 10 10
BRD 2 -14 -1 -13 / 10 10 10 10
HYR 15 -8 4 -12 / 60 10 10 10
ASX 17 -4 4 -12 / 60 50 10 10
&&
.DLH WATCHES/WARNINGS/ADVISORIES...
MN...WIND CHILL ADVISORY FROM 6 PM THIS EVENING TO 11 AM CST TUESDAY
FOR MNZ010>012-018>021-025-026-033>038.
WI...WIND CHILL ADVISORY FROM 6 PM THIS EVENING TO 11 AM CST TUESDAY
FOR WIZ001.
LS...SMALL CRAFT ADVISORY FROM 4 AM TO 10 PM CST TUESDAY FOR LSZ121-
146>148.
&&
$$
EOM/DONOFRIO
